臺灣博碩士論文加值系統

多天線系統為未來無線通訊系統的主流，但多天線有高功耗,大體積,高成本的缺點，因此多頻操作天線為未來的趨勢。由於傳統矩形微帶天線不具備全向性之輻射場形，手機無法使用。因此本論文提出全向性輻射可雙頻操作之手機天線，可雙頻操作之倒S形偶極微帶天線。
其概念乃利用折疊線狀偶極天線的方式藉以扭曲原不可廣播操作之輻射模態，成為單波束可操作之輻射場形.因而可雙頻操作.且為全向性可用於手機。
實驗結果，倒S形偶極微帶天線於總長12公分以上具備可輻射雙頻率之特性，而操作頻率由總長度決定。且頻率並非與長度精確相依，會因阻抗匹配因素而有微調現象。理論分析以向量磁位積分的方式求取輻射場形與電流分佈,大體上已可掌握倒S形偶極微帶天線之操作特性,再加上以實驗之方法輔助分析，可掌握設計之方法。但因阻抗匹配不易因此長度過短時雙頻之特性將消失。由於對稱性之結構因此可作為其他形線狀偶極微帶天線理論分析之基本構型，更因為依據Babinet's theory電流偶極天線與磁偶極天線之互補性可作為狹縫式磁偶極微帶天線之理論分析基礎與設計工具。具備低輻射功率環保天線之優點，因低功率之特性使得符合低輻射功率要求之現代室內環境。
因倒S形偶極微帶天線為對稱形結構因此頻率可調性受限，且為應用於較高功率高頻之需求，第五章另外提出迴紋針形偶極微帶天線，雖然輻射場形略有缺陷但不影響全向性輻射之基本特性，足夠商用之需求，依據數據顯示可三頻操作如第五章，且操作頻率皆符合-13dB符合較高功率室外機之需求，因本論文並未提出迴紋針形偶極微帶天線詳細之理論分析，相關之操作方式尚有待進一步之理論分析加以探討，因泛迴紋針形偶極微帶天線之基本構型為倒S形偶極微帶天線因此本論文對倒S形偶極微帶天線之理論分析包含實驗分析之方法皆可作為將來對泛迴紋針形偶極多頻微帶天線分析之參考依據。

Multi-antenna systems will be tendency of future wireless communication systems, but multi-antenna systems have high power, huge size, high-cost disadvantage, so multi-frequency operation of antennas is future trend. As traditional rectangular microstrip antenna does not have omni-directional radiation pattern, cannot be used on cell phone. Therefore, this thesis presents omni-directional radiation pattern antenna for cell phone, it can be operated for dual band frequency the inverse S-shape microstrip dipole antenna. This concept is to fold linear dipole antenna in order to distort radiation pattern from non-broadcasting pattern to broadcast pattern. From two beams radiation pattern change to single beam radiation pattern. So can be used on the omni-directional cell phone and for dual-band operation.
According to Experiments, the inverse S-shape dipole microstrip antenna can be operated for two-band at length longer than 12 cm and operating frequency is determined by total length. But resonated frequency and length are not really linear dependent, changed a little by impedance matching. Theoretical analysis use magnetic vector potential to perform a radiation pattern and current distribution. Already know inverse S-shape microstrip dipole antenna operating characteristics, with experimental methods analysis, then can handle design methods. But impedance matching is difficult, when length is too short dual band will disappear. Because of symmetric structure so can be linear fold dipole microstrip antennas basic model. And because of Babinet's theory, also can be used as magnetic dipole slit microstrip antenna theoretical analysis and design model. The inverse S-shape dipole microstrip antenna has low power characteristics, so can be environmental antenna. Matching modern low-radiation indoor environment.
Because inverse S-shaped microstrip antenna is symmetrical dipole structure so frequency tunability is limited, and because need to be operated in high power situation. The fifth chapter also propose pan-paper clip shape dipole antennas, although the radiation patterns not perfect but does not affect basic characteristics of omni-directional radiation pattern, enough commercial demand. According to simulate data can be tri-band operated such as chapter fifth, and frequencies of operation are under -13dB matching for high power outdoor model. Because this thesis did not make pan-paper clip-shape microstrip dipole antennas detailed theoretical analysis, these antennas’ characteristics still need to be studied. Because inverse S-shaped microstrip dipole antenna are basic configuration of pan-paper clip-shape microstrip dipole antennas. Therefore, this thesis the inverse S-shape dipole microstrip antenna includes experimental analysis, theoretical analysis method can be used for future pan-paper clip multi-frequency microstrip dipole antennas’ analysis references.

目錄
摘要 i
Abstract iii
致謝 v
目錄 vi
圖目錄 viii
第一章 緒論 1
1-1歷史背景與研究動機 1
1-2 研究目的與分析方式 . 2
1-3論文架構 3
第二章偶極微帶天線之介紹 5
2-1 偶極天線駐波電流分佈 5
2-2電流分佈與輻射場形方程式 6
2-3偶極微帶天線之特性 10
2-4結論 10
第三章 倒S形偶極微帶天線分析 18
3-1. 倒S形偶極微帶天線之輻射場推導 18
3-2. 結果與數據分析 21
3-3. 結論 22
第四章 結構參數改變對倒S形偶極微帶天線之特性的影響 30
4-1長度與對天線特性之影響 30
4-2節不對稱倒S形微帶天線 30
4-3節為結論 31
第五章 36
泛迴紋針形三頻偶極微帶天線 36
5-1泛迴紋針形偶極微帶天線 36
5-2泛迴紋針形偶極微帶天線特性之探討 36
5-3結論 37
第六章 48
結論與討論 48
參考文獻 50



圖目錄
圖1.1 倒s形雙頻偶極微帶天線 4
圖2.1 非共平面微帶式偶極天線側視圖 11
圖2.2  偶極天線及駐波電流示意圖 12
圖2.3 .偶極天線駐波mode2駐波電流圖 13
圖2.4偶極天線共振頻率分佈圖 14
圖2.5偶極天線mode2實際分佈圖 15.
圖2.6 Mode1輻射場形  (a)0.896G (Hz) yzPlane  E Theta (b) 0.896G  xzPlane E Phi 16
圖2.7 Mode2 輻射場形(a) 2.75G (Hz) yz Plane  E Theta  (b) 2.75G (Hz) xz Plane E Phi 17
圖3.1  倒S形偶極微帶天線之結構圖：(a)上視圖,(b)側視圖 24
圖3.2 圖3.1之反射係數，可輻射雙頻，藍色為模擬，紅色為實驗，低頻 1.128G高頻
2.28G (GHz)圖3-1之(a) a=42mm, b=6mm, c=2mm, (b) b=0.5 mm 25
圖3.3  模態二電流分佈 駐波與摺疊結構效應 26
圖3.4圖3.1天線輻射場形(a) 1.128G  yz Plane  (b) 1.128G  xz Plane 27
圖3.5圖3.1之輻射場形  (b) 2.28G   yz plane  (b)2.28G   xz plane 28
圖3.6公式(3.6)解析幾何描點圖(t=linspace(0,2*pi);e=cos(cos(t)-0.1)/0.4;polar(t,e);) 29
圖4.1 12cm不對稱倒S形偶極微帶天線(a)上視圖,a=42mm,b=6mm, c=2mm,d=22mm
(b)側視圖 b=0.5 mm 32
圖4.2圖4.1天線反射係數圖 33
圖4.3圖4.1天線輻射場形 1.36G   (a) yz plane  (b) xz plane 34
圖4.4圖4.1天線輻射場形  2.28G  (a) yz plane  (b) xz plane 35.
圖5.1 迴紋針形偶極微帶天線(a)上視圖,a=66mm,b=6mm, c=42mm,d=22mm (b)側視圖 b=0.5mm 38
圖5.2圖5.1迴紋針形三頻偶極微帶天線反射係數圖 39
圖5.3圖5.1天線輻射場形   1.92G (a)yz plane    (b) xz plane 40
圖5.4圖5.1天線輻射場形   2.91G (a) yz plane    (b) xz plane 41
圖5.5圖5.1天線輻射場形   3.59G (a) yz plane    (b) xz plane 42
圖5.6迴紋針形偶極微帶天線(a)上視圖,a=66mm,b=6mm,c=42mm,d=22mm,e=59.5mm,
f=0.13mm (b)側視圖 b=0.5 mm 43
圖5.7圖5.6泛迴紋針形三頻偶極微帶天線反射係數圖 44
圖5.8圖5.6天線輻射場形 2.16G    (a)yz plane    (b) xz plane 45
圖5.9 圖5.6天線輻射場形 2.91G.   (a)   yz plane  (b) xz plane 46
圖5.10圖5.6天線輻射場形 3.59G    (a)  yz plane  (b) xz plane 47

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